1. Field of the Invention
This invention relates to a television video signal converting apparatus and, more particularly, to such an apparatus which obtains television video signals from a movie film by means of video signal processing.
2. Description of the Prior Art
Typically, movie film is fed at a rate of twenty-four (24) frames per second. As a result, a frame rate conversion is normally required when images recorded on movie film are converted into television video signals of a standard format, for example, an NTSC television signal format. More specifically, in so-called "tele-cine" work in which the images of a movie film are converted into an NTSC television video signal having 30 frames per second (60 fields per second), frame number conversion is carried out according to a so-called "2-3 pulldown conversion system".
Thereafter, if the converted NTSC television video signal is to be recorded on movie film using, for example, an electron beam image recording system, a frame number conversion which is opposite to the previously described number conversion is carried out.
Thus, in the above situation, a frame number conversion is carried out twice. As a result, the frames of the final movie film may not correspond to those of the original movie film. Accordingly, during the reproduction or projection of the final movie film, the movement of the images from the frames may not correspond to that of the images from the frames of the original movie film and, as a result, the projected image may appear to flicker or sway. The unpleasant phenomenon is very difficult, if not impossible, to avoid completely when using this method.
However, this unpleasant phenomenon may be eliminated by using the following method. More specifically, the "tele-cine" work is carried out with the movie film being fed at a rate of 30 frames per second. Thereafter, the movie film, upon which the television video signal is to be recorded, is fed at the same rate of 30 frames per second. Therefore, in this case, the frame number conversions can be eliminated.
However, the above described method has a disadvantage. More specifically, the television video signal obtained through use of the "tele-cine" has a movement component 1.25 times as fast as the original one. Therefore, when the television video signal obtained through "tele-cine" work and a television video signal having a movement component of normal speed are combined, the resultant composed television video signal is unavoidably unnatural in appearance. Thus, this method is unacceptable.